RFR: JDK-8035751 Clean up Visual Studio detection logic

[Erik Joelsson]

I think it looks good overall and it's good to clean this up.

toolchain_windows.m4:
204: not your change but the typo stings my eyes and could be fixed 
while in the area. (corrent?)

I wonder if it would be better to move the deletion of the temporary 
script files to later in the function so that they are still around if 
it fails, for easier debugging?

/Erik

On 2014-03-24 12:04, Magnus Ihse Bursie wrote:
> This bug was triggered by the issue in JDK-8035725. Had the VS 
> detection logic been more transparent, that bug would not have had to 
> happen.
>
> We need to rewrite the VS detection so that it is much more 
> controlled, and do not run an unchecked shell script that modifies 
> arbitrary environment variables. We can never re-create the same 
> circumstances during "make time" as we have during "configure time" in 
> that case. Instead, we should systematically set only those variables 
> that are actually needed.
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8035751
> WebRev: 
> http://cr.openjdk.java.net/~ihse/JDK-8035751-clean-up-visual-studio-detection/webrev.01
>
> /Magnus